
#region License

// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;

namespace HmFramework.Text
{

	/// <summary>
	/// Builds a String. Unlike StringBuilder this class lets you reuse it's internal buffer.
	/// </summary>
	internal class StringBuffer
	{

		private Char[] _buffer;
		private Int32 _position;
		private static readonly Char[] EmptyBuffer = new Char[0];

		public Int32 Position
		{
			get { return _position; }
			set { _position = value; }
		}

		public StringBuffer()
		{
			_buffer = EmptyBuffer;
		}

		public StringBuffer(Int32 initalSize)
		{
			_buffer = new Char[initalSize];
		}

		public void Append(Char value)
		{
			// test if the buffer array is large enough to take the value
			if (_position == _buffer.Length)
				EnsureSize(1);
			// set value and increment poisition
			_buffer[_position++] = value;
		}

		public void Append(Char[] buffer, Int32 startIndex, Int32 count)
		{
			if (_position + count >= _buffer.Length)
				EnsureSize(count);
			Array.Copy(buffer, startIndex, _buffer, _position, count);
			_position += count;
		}

		public void Clear()
		{
			_buffer = EmptyBuffer;
			_position = 0;
		}

		private void EnsureSize(Int32 appendLength)
		{
			Char[] newBuffer = new Char[(_position + appendLength) * 2];
			Array.Copy(_buffer, newBuffer, _position);
			_buffer = newBuffer;
		}

		public override String ToString()
		{
			return ToString(0, _position);
		}

		public String ToString(Int32 start, Int32 length)
		{
			// TODO: validation
			return new String(_buffer, start, length);
		}

		public Char[] GetInternalBuffer()
		{
			return _buffer;
		}
	}
}